Pediatric stroke survivors had an absolute risk of 39% for developing epilepsy in the 10 years following their stroke in a review of 371 patients in Northern California.

Two factors significantly boosted a child’s risk of developing epilepsy following a stroke: A seizure at the time of stroke, and a neurologic deficit at the time of hospital discharge following the index stroke, Dr. Christine Fox said at the International Stroke Conference (Stroke 2012;43:A41)

Although these findings have no immediate management implications, the information could help parents know what to expect when their child has a stroke.

Epilepsy “is not always one of the first outcomes we think about when we speak with parents,” said Dr. Fox, a neurologist at the University of California, San Francisco. “If there is such a high incidence of epilepsy after stroke, maybe it’s something to talk about with parents,” she said in an interview.

The study reviewed used data collected in the Kaiser Pediatric Stroke Study, run by Kaiser Permanente of Northern California, and included children who ranged from neonates to 19 years old and had a clinical presentation and brain imaging results consistent with a stroke. The group included hemorrhagic and ischemic strokes occurring during 1993-2003, and arterial ischemic strokes during 2003-2007. This cohort consisted of 371 children who survived a stroke to hospital discharge, including 110 neonates and 261 older children who had 226 ischemic strokes and 145 hemorrhagic strokes.

During a median follow-up of 4.5 years, 89 of these children developed epilepsy, defined as a confirmed, unprovoked seizure occurring more than 30 days following the index stroke. The researchers excluded 7 of the 89 incident epilepsy cases because they had a history of seizures prior to their stroke. Survivor analysis of the 82 new-onset cases showed an average annual incidence of 6%, with a cumulative 5-year incidence of 23% and a cumulative 10-year rate of 39%, Dr. Fox said.

A multivariate adjusted analysis that controlled for factors such as age, sex, race, and type of stroke identified two parameters linked with a significantly higher risk for developing epilepsy following stroke: a seizure concurrent with the stroke ictus, which boosted the risk of subsequent epilepsy 3.6-fold, and a neurologic deficit at discharge, which increased the risk for later epilepsy twofold.

In contrast to these findings, previous reports documented a much lower incidence of epilepsy in adults following a stroke, with a 3% rate after 1 year, and an 8% rate after 5 years, Dr. Fox said.

Dr. Fox said that she had no disclosures. The conference was sponsored by the American Heart Association.